Vibkatory conveyer for packing



Dec. 26, 1950 J. FREl, JR

VIBRATORY CONVEYER FOR PACKING Filed May 2, 1947 Patented Dec. 26, 1950UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to a vibratory conveyor for packing finelydivided material.

While the conveyor of my invention may be advantageously employed forthe shaking down and packing of various types of divided material, it isparticularly well adapted for use in connection with silica sand or thelike, which is employed to form a mold for use in casting operations.When the article to be cast must be of precise dimensions and thematerial of which the articles are cast is extremely hard, it isimportant that they be cast accurately so that a minimum of grinding orother cleaning operations are required, since such operations aredifficult, time-consuming and expensive. It is desirable, therefore, toprepare a mold which will provide a mold cavity having a smooth surfaceand a surface free of hollows produced by entrapped fluids, such as airor liquids, which attach themselves to the pattern during the formationof the mold. When the finely divided investment material, which isemployed to form the mold, is distributed in fluid form about thepattern in a flask, bubbles of air or other gas entrapped in theinvestment material may attach themselves to the pattern and therebydisplace the investment material at that location. Thereafter, when themold-containing flask is heated to melt or burn out the pattern, themold cavity has one or more unwanted hollows which will be filled withmolten metal during the casting operation, with the result that thecasting is imperfect. Expensive cutting or grinding operations may thenbe required to put the casting in usable form, or else it may benecessary to discard the casting entirely.

It is a principal object of my invention to remove from the investmentmaterial, as it is setting about the pattern, all gases which mightspoil the configuration of the casting.

It is another object of my invention to cause the investment material tobe closely and firmly packed throughout the mold and especially aboutthe pattern so that the mold will be strong and so that a smooth castingwill be produced.

In the accomplishment of the foregoing objects, I cause themold-containing flask to be vibrated more strongly at first and then indiminishing amounts. The initial rougher vibrations are desirable fordriving out entrapped gases, but are not as satisfactory for settlingand packing the investment material in the flasks. By reducing thedegree of vibration after gases have been eliminated from the mold, itis possible toform a densely and uniformly packed mold 2 and to bringexcess liquid to the surface of the mold.

It is another object of my invention to provide means for consistentlyproducing many molds of uniform density and accuracy. In accomplishingthe foregoing object, I provide mechanism which subjects each mold tothe same amount of vibration for the same periods of time.

It is still another object of my invention to provide vibratingmechanism, the degree of vibration of which may be varied for differentmixtures of liquid and varying sizes of finely divided particles ofinvestment material. Other objects, uses and advantages of my inventionwill become apparent from the following description when taken with theaccompanying drawings in which:

Figure 1 is an elevational view of the vibratory conveyor of myinvention together with driving means therefor; and

Figure 2 is a sectional view on line 2-2 of Figure 1.

Referring now to the drawings, the vibratory mechanism, which will bereferred to as a vibratory conveyor, is indicated generally by thereference numeral ID. A mounting plate or board l2, adapted to be restedupon or secured to a supporting surface, has a plurality of verticallyextending pairs of posts l4, I4, I6, l6 and I8, I8. Each of the postshas an extension of reduced diameter at its upper end which extension isthreaded. The extensions 20 of the posts l4 may carry nuts 22 while theextensions 24 of posts l6 and extensions 26 on the posts 18 carry nuts28 and 30, respectively. The nuts 22, 28 and 30 are usually located withtheir upper surfaces in a common, horizontal plane so as to support aplate 32 in horizontal position, when it is not being vibrated.Apertures through the margin of the plate 32 permit said plate to bepositioned over the threaded extensions 20, 24 and 26 so that it restson the nuts 22, 28 and 36. Above the board on each threaded extensionare positioned a pair of lock nuts, which, when in engagement with eachother, prevent both nuts of each pair from being vibrated from theirselected position. The pairs of lock nuts for each of the pairs of postsM, It and [8 are indicated by the reference numerals 34, 36 and 38,respectively.

The distance between the nuts 30 and cooperating lock nuts 38 of theposts I8 is greater than the corresponding distance between the nuts 28and 36 of posts I6, and the nuts 22 and 34 of posts l4. Also, thedistance between nuts 28 and 36 of the intermediate posts [6 is greaterthan that between the nuts 22 and 34 of posts l4. Consequently verticalmovement of plate 32 along the extensions 20, 24 and 26 of thesupporting posts, is permissible with the right-hand end of the plate,as viewed in Figure 1, being permitted the greatest amount of verticalmovement, and the mid-portion of the plate 32 being permitted an amountof vertical movement about one-half of that permitted at the posts I8.

Vibrating means, indicated generally by. the reference numeral 44, issecured to the underside of the plate 32 nearer the end of the platewhich is permitted the greater amount of vertical movement. Thevibrating mechanism, by

way of example, may comprise an electric motor 46 having a pulley wheel58 carried by the drive shaft, which pulley wheel carries a pin 50.

pivoted to the periphery of the pulley wheel 28. The pin 50 forms aneccentric and thereby causes the motor and its frame-to vibrate when themotor 4'6 is running, with the result thatthe plate 32 is vibrated. Theforce of the vibrations may be varied by varying the length of the-pin.The plate is vibrated primarily in a vertical direction becausethe'apertures inthe margin of the plate 32 are substantially the samewidth as tire diameter of th extensions on the posts i l, l5 and 18.However, some lateral .motion tends to be transmitted to the plate-32during the. onerationof said motor. Although I have shown the vibratingmeans M as being fastened to the under side of the plate 32, other meansmay be employed to impart a vibratory motion to the plate-and said;other means need not be supportedrdirectly by the plate 32. It will beunderstood that in the preferred" form ofmy invention, whatever thevibrating means may be, it will be-applied nearer the end of the platewhich is permitted the greater amount of vibratory movement.

An endless conveyor belt Elguidedby idling rollers 54 and driven by theshaft 55 passes over the-upper surface --of the plate 32. Mechanism fordriving th drive shafttii isindicated generally; by the referencenumeral and may take any" one of a'number of'forms. In the illustratedembodiment shaft as is connected-with thelarge pulley wheel 58 which;through pulley belt 62,-is'connected with a smaller pulley wheel (notshown) carried by a shaft'of a gear reduction unit-54. The gearreduction unit can directly connected with the drive shaft of anelectricmotor 66. It will be noted that the conveyor belt 52 moves in thedirection indicatedby the arrow A, that is, in a direction such that itenters-upon 'the surface of the vibratory plat -32 at that end which ispermitted the greater amount of vibratory movement. Pairs of posts d5along opposite longitudinal marginsof the-plate 32 s port a pair ofparallel guide rails 62 for g flasks, such as flasks H5, in theirmovement along plate 32. Thebelt 52 passes between the posts dll and maybe guided therebyin its passage across the plate. At the left-hand endof th vibratory conveyor it, there may be positioned a board or-table 58which is sufficiently close to the belt 52*at the'end of its horizontaltravel that objects carried by said conveyor belt may readily pass ontosaid table $8;

As will be readily apparent, the plate 32 vibrates at the right-handend; as viewed in Figure 1, to a greater extentthan-it does at any otherpart, and the extent of the vibrations supplied will depend upon thenature of the object to b'e vibrateda Where a:moldcontainingdiask I5 isbeing passed along the board 32, the amount of vibration selected willdepend in part upon the mixture of liquid and mold forming material. Thegranular size of the sand or other investment material will be anotherfactor governing the amount of vibration desired.

In the operation of m vibratory conveyor, the vibrating means 4 will bestarted and the driving means 58 for the conveyor belt 52 will bestarted, so that the belt will be traveling over the board at apredetermined uniform rate of speed. Flasks containing freshly pouredinvestment material will be placed upon the plate 32 at its right-handend, as viewed in Figure 1, so that initially the flasks will bevibrated extensively and to such a degree that air and other gases willbe driven from'the investment material. As the belt .52 carries theflask along the plate 32, the vibrations will be of decreasing amountsince, once the gases are driven .from the investment material; the.investment material will be better settled and packed about the patternwhen vibrated a lesser amount. I have found that clearance between theplate and nuts of of an inch at the posts [8, A of an inch attheintermediate posts It, and ofan inch at the posts i l will provide theproper vibration of mold-containing flasks as they pass along the plate32. Rails 42 provided along the longitudinal margins of the plate 32prevent the flasks from sliding oif sideways and becoming spilled orbroken. Iprefer to employ the vibratory conveyor in such fashion thatflasks are continually being added at the end of the plate having. thegreatest amount of vibratory movement while, at the end having the leastamount of movement, th vibrated flasks are being removed or collected onan adjacent table, such as table 68. Whilethe force of vibrationstransmitted from the vibrating mechanism at to the plate 32 may bevaried by varying the.

length of the pin 59, which is secured to the pulle wheel 58 of motorGE, the extent of the vibrations;-willstill be controlled by thelocation of the nuts on the-threaded extension on the pairsofsupportingposts l4, l6 and- I8.

Thecadvantageof having a conveyor belt transporting the flasks acrossthe plate 32 resides inthefact that :a uniform rate of passage acrcssthe plate 32 istherebypossible. This results in each mold being ofuniform density and accuracy, a great advantage in the production ofprecision castings in quantity. Howeventhe flasks could be. transmittedalong. the vibrating board without the conveyor belt'521if the. lowernuts. 22;. 28 and 33 on the posts l4; l6 and l8irespectively, were soadjusted -relative to each other that the common plane of their uppersurfaces werev at an angle with respect to the. horizontal and inclineddownwardly toward-the'lelt hand end, as viewed in-Figure 1, ofthevibratory plate 32'. Gravity would, in this arrangement; cause theflasks to pass along thevibrating-plate 32 from the end having thegreater amountof vibration, to the end having the lesser amount. Causinthe flasks to travel in this manner will not, however, result inv theirbeing vibrated a uniform amount because offthe. rate of -th'eirrpassagealong the plate 32will not be uniform.

Although I'have illustrated a preferred embodimentofmyinvention, I do.not intend to be limited theret except insofar as the appended claimsare soulimited, since modificationcoming within the scopepf the claimswill suggest themselves to others =byreason of this-disclosure.

I claim:

Vibrating mechanism comprising, in combination, a longitudinallyextending plate adapted to be vibrated, a retainer rail along each sideof the plate, supporting posts positioned adjacent the ends and themiddle of the plate and having threaded extensions of reduced diameterpassing through apertures in the margins of the plate, adjustable nutscarried on said extensions to control vertical movement of the plate onthe extensions of the supporting posts, said nuts being adjusted topermit greater vibratory movement of said plate at its one end than atits other end, vibrating means for vibrating the plate, and an endlessconveyor passing over the plate between the retainer rails and adaptedto carry objects to be vibrated along said plate from the end having thegreater vibratory movement to the end having the lesser vibratorymovement.

JOHN FREI, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

